Our 2005 Fabia hatchback (1.2 HTP) failed it's MOT both last year AND this year because the central brake light had failed.

I thought these were LEDs and supposed to be really reliable? We haven't had to change any other bulbs, just this (expensive!) one twice.

Anyone else had the same problem?

ISTR there being a fault with the switch on the pedal that causes problems with the high-level brakelight. Maybe THAT's what's actually at fault?

Question , why is the high level back light stop a failure , i thought MOT just required the 2 rear stop lights .

Just tap a bulb into the feed to the high light, see if it's the unit or the switch?

If the other bulb lights, just tape it to the windscreen for the MoT until you've fixed it?

I think that as long as one of the "bulbs" works in the high level brake light, then its a pass - remember these high level brake lights are mandated fitment now from 199? onwards.

Question , why is the high level back light stop a failure , i thought MOT just required the 2 rear stop lights .

Any and all lights attached to the car and wired in must be working in order for it to be roadworthy. For instance, if you have fog lights (optional), and one of them isn't working, the police can actually pull you over and give you a £60 ticket & 3 points for defective lights (although they should use their discretion, and issue with a vehicle rectification order, giving you 7 days [iIRC] to fix it and present it, if the vehicle is in otherwise good condition).

ISTR there being a fault with the switch on the pedal that causes problems with the high-level brakelight. Maybe THAT's what's actually at fault?

That would stop all 3 brake lights working... and the central brake light is actually wired from one (offside IIRC) of the other brake lights.

ALL the LEDs stop working, replacing the assembly (LEDs and circuit board) makes them work for about 9 months, but then as soon as the cold weather returns they stop working again - 2 years in a row.

Edited 2 February, 201016 yr by PetrolDave

Any and all lights attached to the car and wired in must be working in order for it to be roadworthy.

Correct.

Last year the inde we use removed the central brake light since they couldn't get the part the same day, which meant they were able to issue an MOT pass - since all the lights that were fitted worked.

We returned the next day for them to fit a replacement central brake light.

Ah, but if the brake light switch is faulty it might be causing a voltage spike or similar killing the high level light.

What is the cost of these btw?

That would stop all 3 brake lights working... and the central brake light is actually wired from one (offside IIRC) of the other brake lights.

ALL the LEDs stop working, replacing the assembly (LEDs and circuit board) makes them work for about 9 months, but then as soon as the cold weather returns they stop working again - 2 years in a row.

I'm pretty sure it's what happened to the vRS that Autocar had on long-term test, and it's definitely worth considering, as the switch is only a tenner, and it's a simple-enough DIY job if you have a set of Torx heads and a trim remover (even if you had to buy them, it's still going to be less than twenty quid all-in!) Follow steps 1-9 here, and just replace the brakelight switch instead of the clutch switch...

Clicky Linky

My vRS had started to bring the light on the dash telling me there is a bulb gone and it turns out the LED light has 4 LED's that work when they want too.

I might have to get a new LED strip and replace it, although, they do come on if you bang it hard.

Most things start to work if you bang them hard enough.

Anyone know the cost of a light?

Ben

Anyone know the cost of a light?

Ben

I'm guessing PetrolDave does... :(

See http://www.motuk.co.uk/manual_130.htm , and read down the "Information" column to "High Level Stop Lamps"

Never knew that, thanks.

MOT isn't until November anyway but I'll get a new one now.

Ben

I'm pretty sure it's what happened to the vRS that Autocar had on long-term test, and it's definitely worth considering, as the switch is only a tenner, and it's a simple-enough DIY job if you have a set of Torx heads and a trim remover (even if you had to buy them, it's still going to be less than twenty quid all-in!) Follow steps 1-9 here, and just replace the brakelight switch instead of the clutch switch...

Clicky Linky

What is the point in replacing the brake light switch when BOTH the normal brake lights still work?

Check the wiring diagram and you'll see that replacing the brake light switch is a total red herring, since if the brake switch is at fault then those won't work either.

Edited 2 February, 201016 yr by PetrolDave

I'm guessing PetrolDave does... :(

£22.35 plus 1/2 hour labour to fit plus VAT - making a total of over £60.

What is the point in replacing the brake light switch when BOTH the normal brake lights still work?

Check the wiring diagram and you'll see that replacing the brake light switch is a total red herring, since if the brake switch is at fault then those won't work either.

Your logic only holds if the failure mode of the switch is open-circuit or closed-circuit. But as has already been pointed out by another member, faulty contacts in the switch are quite capable of causing voltage spikes that won't have any effect on the filament lamps that are used for the brakelights, but which could quite possibly blow the LEDs used in the high-level light. The simple fact is that there isn't much in the circuit other than a fuse, the two filament brake lights, the high-level light and the switch. If two LED units have blown, but the the filament lamps are working OK, then there isn't a whole lot else to check. Either the switch or some wider voltage regulation issue that will be picked up by a fault code scan. After all, as Sherlock Holmes put it, 'Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth.'

Your logic only holds if the failure mode of the switch is open-circuit or closed-circuit. But as has already been pointed out by another member, faulty contacts in the switch are quite capable of causing voltage spikes that won't have any effect on the filament lamps that are used for the brakelights, but which could quite possibly blow the LEDs used in the high-level light.

As a Chartered Electronics Engineer with 35 years experience (10 in the automotive industry) I ignored that suggestion because it is so implausible as to stretch the realms of reality.

The maximum voltage spike that could be generated is twice the supply voltage, and that is not going to cause at least 3 LEDs to fail (the LEDs are in 3 chains of 4 LEDs in series) - they are more than capable of withstanding a spike of around 25 volts.

Well I suggest you trade your car in then, because if you can't fix it with all your knowledge and experience, I doubt anyone else can...

Sorry for trying to be helpful and for passing on the information from reputable publications...

Well I suggest you trade your car in then, because if you can't fix it with all your knowledge and experience, I doubt anyone else can...

Sorry for trying to be helpful and for passing on the information from reputable publications...

All I asked was has anyone else experienced this problem, I didn't ask for a diagnosis.

It appears that only 1 owner has for sure, and maybe one run by Autocar (who I will be contacting) - so I'm led to conclude that it's not a common problem.

Come on now, let's not get heated about it.

I don't think this is a common problem or it would be reported on here more, but I'm changing the light at the weekend and it should all be better.

Sometimes the light doesn't come on at all (the normal brake lights still do though) and as I said earlier, if you bang it hard it works.

What's annoying me more is the sodding light on the dash randomly beeping

Ben